Re: [Qemu-devel] [PATCH v3 3/4] numa: Reject configuration if CPU appears on multiple nodes

[Igor Mammedov <imammedo@redhat.com>]

On Thu, 12 Feb 2015 15:50:34 -0200
Eduardo Habkost <ehabkost@redhat.com> wrote:

> Each CPU can appear in only one NUMA node on the NUMA config. Reject
> configuration if a CPU appears in multiple nodes.
> 
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
> v1 -> v2: (no changes)
> 
> v2 -> v3:
>  * Rename present_cpus to seen_cpus, to make it less confusing
>  * Use GString and error_report() instead of multiple fprintf() calls
With comment below fixed:
Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  numa.c | 37 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 37 insertions(+)
> 
> diff --git a/numa.c b/numa.c
> index 4139e46..712faff 100644
> --- a/numa.c
> +++ b/numa.c
> @@ -168,6 +168,41 @@ error:
>      return -1;
>  }
>  
> +static char *enumerate_cpus(unsigned long *cpus, int max_cpus)
> +{
> +    int cpu;
> +    bool first = true;
> +    GString *s = g_string_new(NULL);
> +
> +    for (cpu = find_first_bit(cpus, max_cpus);
> +        cpu < max_cpus;
> +        cpu = find_next_bit(cpus, max_cpus, cpu + 1)) {
> +        g_string_append_printf(s, "%s%d", first ? "" : " ", cpu);
> +        first = false;
> +    }
> +    return g_string_free(s, FALSE);
> +}
> +
> +static void validate_numa_cpus(void)
> +{
> +    int i;
> +    DECLARE_BITMAP(seen_cpus, MAX_CPUMASK_BITS);
> +
> +    bitmap_zero(seen_cpus, MAX_CPUMASK_BITS);
> +    for (i = 0; i < nb_numa_nodes; i++) {
> +        if (bitmap_intersects(seen_cpus, numa_info[i].node_cpu,
> +                              MAX_CPUMASK_BITS)) {
> +            bitmap_and(seen_cpus, seen_cpus,
> +                       numa_info[i].node_cpu, MAX_CPUMASK_BITS);
> +            error_report("CPU(s) present in multiple NUMA nodes: %s",
> +                         enumerate_cpus(seen_cpus, max_cpus));;
> +            exit(1);
s/1/EXIT_FAILURE/

> +        }
> +        bitmap_or(seen_cpus, seen_cpus,
> +                  numa_info[i].node_cpu, MAX_CPUMASK_BITS);
> +    }
> +}
> +
>  void parse_numa_opts(void)
>  {
>      int i;
> @@ -245,6 +280,8 @@ void parse_numa_opts(void)
>                  set_bit(i, numa_info[i % nb_numa_nodes].node_cpu);
>              }
>          }
> +
> +        validate_numa_cpus();
>      }
>  }
>